Fourier's *Théorie analytique de la chaleur* is available online [here][1]. As an advantage, the English version *The Analytical Theory of Heat* is available [here][2].


  [1]: http://archive.org/stream/thorieanalytiqu00fourgoog#page/n11/mode/2up
  [2]: http://archive.org/stream/analyticaltheor00fourgoog#page/n6/mode/2up